Yoy have a perfectly valid point and sounds simple but its not that simple. Why? People are well.......people!
Heres what I mean Everyone that has a Driver's License took a test that says yeild right of way, don't speed, stop at a stop sign, and now don't text and drive and well here we are.
My observation is just what I have seen as a FLETC certified Firearms instructor and now teaching occasionally in the private sector as well as seeing a variety of skill levels in matches etc. Firearms training (or peoples skill and ability to grasp) is a triangle. Most folks at the top have mastered and are squared away and can safely do all handling drills safely, weak hand stuff etc But most of the bottom 3/4 need work and a majority of those think they got it but don't.
I agree.
Also agree that it's not simple. There are a lot of folks out there running around that don't know what they don't know. They have gotten away with bad habits for long enough that they believe their way is the right way. Not to mention that often we gun carriers are type A personalities.
And, with all due respect, a lot of the safety culprits are those looked up to for their career and experience. Law enforcement and military are frequently part of the problem, if they don't train beyond their requisite or compete in shooting sports. I'm sure you have seen this as I have.